Explaining the PLA’s Record-Setting Air Incursions Into Taiwan’s ADIZ

From October 1 to 4, Chinese military incursions into Taiwan’s air defense identification zone (ADIZ) were unprecedented in scale and intensity since the Taiwanese Ministry of National Defense (MND) made such data publicly available last September. On October 1, the People’s Liberation Army (PLA) launched a 25-plane incursion during the day, followed by another 13-plane incursion that night, setting a record for the largest number of sorties flown by the PLA into Taiwan’s ADIZ in a single day. However, that record was broken the very next day (October 2) when the PLA flew a total of 39 sorties in two waves – one during the day and the other at night. The incursion on October 3 involved “only” 16 planes but on October 4 the PLA set a new record for the single largest sortie conducted to date (52), as well as the largest one-day sortie record (56) when the second, night-time incursion is included.

Over the course of first four days in October, the PLA carried out a total of 149 sorties into Taiwan’s southwestern ADIZ – a staggering 28 percent increase already over September’s previous record for total sorties (116).

What explains this increase in ADIZ incursions? The PLA carries out these aerial incursions for multiple reasons – from signaling Beijing’s displeasure at closer Taiwan-U.S. ties to focusing on its “anti-access” and maritime deterrence strategy. On October 4, Beijing broke its silence regarding the aerial incursions by responding to the United States’ October 2 statement condemning the incursions. China blamed the U.S. for being provocative and harming regional peace, with its arms sales to Taiwan and warships sailing regularly through the Taiwan Strait.

Our analysis of the incursions data, however, suggests that there is no correlation between U.S. arms sales to Taiwan and any increase in ADIZ sorties. Also, the PLA has no previous record of responding to U.S. or allied warships transiting the Taiwan Strait with incursions of this magnitude. Instead, any Chinese response to a foreign warship transiting through the strait typically takes place on the Chinese side of the Median Line, and is not reported by Taiwan’s MND. Nonetheless, the spike in early October was Beijing clearly signaling its displeasure over one of its key “red line” issues.

A nationalistic show of force or intimidation of Taiwan on the occasion of China’s National Day (October 1) for propaganda purposes is a very plausible. Of the two formations intruding into the ADIZ, the one that took place at night was particularly interesting in that it lacked the typical signs pointing to a maritime strike focus. Moreover, the formation, which included two H-6 bombers, 10 J-16 fighters, and a KJ-500 AEW&C aircraft, also lacked other critical capabilities often associated with PLA incursions, like electronic warfare and ISR support. The first incursion of the same day, however, resembled closely other formations observed in the past with a maritime strike focus. Indeed, a Global Times editorial stated that the PLA’s incursions “are not only a severe warning to the secessionist Democratic Progressive Party (DPP) authorities on the island, but also clearly portrayed the severity of the situation across the Taiwan Straits, and at the same time gave a clear warning to the supporters of the DPP authorities.”

Beijing and Taipei have been in a war of words over Taiwan’s application to join the CPTPP trade pact, which China vociferously opposes. Also, as October 10 marked the 110th anniversary of the Republic of China it is also possible that Beijing was stepping up the incursions as a warning to President Tsai Ing-wen (and also the U.S.) not to use the occasion to do something provocative (such as changing the name of the Taipei Economic and Cultural Representative Office, TECRO, in Washington, DC).

Another possibility is that the PLA’s sorties were timed to coincide with a naval exercise south of Okinawa, in the Philippine Sea, that brought together three aircraft carriers – USS Ronald Reagan, USS Carl Vinson, and HMS Queen Elizabeth – as well as JS Ise, a Japanese helicopter destroyer, along with 14 other naval vessels from the U.S., Japan, the United Kingdom, New Zealand, the Netherlands, and Canada. The exercise certainly raised the PLA’s interest as it demonstrated the formation of a potential coalition against Chinese aggression in the Indo-Pacific. The naval exercise concluded on October 3, as the PLA dispatched 16 aircraft into Taiwan’s ADIZ.

Several previous large-scale incursions have a likely connection to U.S. naval presence, operations, and exercises. For example, between, September 3 and 5, Chinese aircraft conducted three incursions, each involving at least one KQ-200 and two or more anti-shipping capable combat aircraft, suggesting a strong maritime strike focus. The largest of the three incursions took place on September 5, during which 19 Chinese aircraft flew into Taiwan’s southwestern ADIZ, including a KQ-200, four H-6 bombers, 10 J-16 and four Su-30 fighters. Importantly, the USS Carl Vinson Carrier Strike Group and USS America Expeditionary Strike Group were known to have operated in the vicinity of the Luzon Strait.

Earlier, on August 17, 11 PLA aircraft intruded into Taiwan’s ADIZ, including again a KQ-200, a Y-8 EW, a KJ-500 AEW&C, six J-16, and two H-6K bombers. The incursion had a likely connection to the large-scale naval exercise, LSE-21, involving assets from the United States and Australia, which were recorded to be present not far from the Taiwan Strait during the intrusion.

More to the point, on October 4, the largest incursion to date, involving 52 aircraft, was very likely related to the HMS Queen Elizabeth and USS Carl Vinson CSGs passing through the Bashi Channel to the South China Sea. This record-breaking incursion had arguably a strong maritime strike focus, with the involvement of two KQ-200s, 12 H-6 and 34 J-16 anti-shipping capable tactical aircraft, two Su-30 fighters, and a KJ-500 AEW&C. Moreover, the MND data on the aircraft’s flightpaths further suggests a maritime strike objective with focus toward the Bashi Channel.

The relative quiet in PLA incursions since October 4 is particularly interesting.

The days leading up to Taiwan’s National Day (October 10) saw only minor incursions involving one to three aircraft. Most of these incursions represented now well-established training sorties and other frequently observed missions. It is noticeable that the PLA left Taiwan alone during the 2020 National Day as well. Based on the data and identified patterns of behavior it is difficult to assert with any certainty the reason behind PLA’s quiet during this notable event in the island’s political calendar. This is especially stark when compared to the massive increase of PLA activity during China’s own national day.

Beijing could very well have used the Wall Street Journal’s report that the United States has been secretly maintaining a small contingent of military trainers in Taiwan for at least a year as a pretext to renew large-scale incursions. The Global Times called the U.S. deployment an “invasion” and said that China “has the right to carry out military strikes against them at any time.” However, on the eve of Taiwan’s National Day, Chinese President Xi Jinping vowed “peaceful” reunification, saying it best meets the interests of the Taiwanese people. Xi’s remarks came after President Joe Biden acknowledged on October 5 that he and Xi had spoken about Taiwan and agreed to abide by the “Taiwan agreement.”

The lull in incursions also followed the Zurich meeting on October 6 between U.S. National Security Advisor Jake Sullivan and China’s top diplomat Yang Jiechi, where there were “tough and direct exchanges” over the Taiwan Strait. This goes on to demonstrate the difficulty in making any hard and fast conclusions about the PLA incursions into Taiwan’s ADIZ. What we can say is that there are many motivations and reasons for the intrusions, many of which may have little to do directly with Taiwan itself.